Grand Canyon caves, breccia pipes and mineral deposits

Wenrich, K.J.; Sutphin, H.B.

doi:10.1111/j.1365-2451.1994.tb00880.x

Cited by 6 publications

(4 citation statements)

References 2 publications

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“…Finally, it is pivotal to note that the curved habit of gypsum is not only an artifact of crystal growth of laboratory experiments but is observed in natural environments too. 7,15,16 Based on the findings described here, we suggest considering the evaporation rate as a plausible parameter in promoting the curved habit in natural environments overall in evaporitic settings.…”

Section: Effect Of Different Evaporation Rates On Gypsummentioning

confidence: 74%

“…Gypsum (calcium sulfate dihydrate, CaSO 4 ·2H 2 O) is the most abundant sulfate mineral on Earth’s surface and it is found in a wide range of natural and anthropogenic environments, such as hypersaline lakes, sabkhas and saltworks, − soils, desertic regions, and caves. , Noteworthy, widespread gypsum deposition occurred in the geological past, such as in the Paratethys and Mediterranean basins during the Middle and Late Miocene, respectively. , Furthermore, gypsum deposits have also been detected on Mars , and a swallowtail gypsum habit, commonly referred to gypsum twins, has been recently observed by the NASA’s Curiosity Mars rover …”

Section: Introductionmentioning

confidence: 99%

“…Single crystals show acicular, tabular, prismatic, and lenticular habits. In some cases, gypsum can also form distinctive curved crystal structures such as the ram’s horn gypsum found in caves, , and sabre gypsum observed in Badenian evaporitic gypsum deposits . Twinning is an epitaxial phenomenon that involves a regular mutual orientation between two crystals of the same phase: the parent (P) and twinned (T) crystals .…”

Section: Introductionmentioning

confidence: 99%

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Effect of Different Evaporation Rates on Gypsum Habit: Mineralogical Implications for Natural Gypsum Deposits

Cotellucci,

Pellegrino,

Costa

et al. 2023

Crystal Growth & Design

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When a solution saturated in CaSO4·2H2O evaporates at room temperature, gypsum crystals precipitate with both single and twinning habits. However, the twinning laws of gypsum involved in this process have long been debated. Recently, easy steps have been described to univocally recognize the twinning laws of gypsum. Therefore, in this study, we have replicated evaporation experiments and focused on identifying these twinning laws. Different precipitation frequencies of gypsum crystals with (i) curved habits and (ii) twins, according to the 100 and 01 penetration twinning laws, have been observed as the evaporation rate increased. The crystal aspect ratio (length/width crystal ratio) might serve as a quick measure for distinguishing between 100 and 01 penetration twinning laws, and the occurrence of these twinning laws in sedimentary environments is suggested. Moreover, high evaporation rates promote curved crystals with both symmetric and asymmetric habits. Based on crystallographic considerations, the asymmetric habit might be explained by a homoepitaxial mechanism, where systematic rotations of the common 2D coincidence cells occur. These results describe which of the twinning laws of gypsum are possible in a pure solution and, for the first time, establish a correlation between different gypsum habits and different evaporation rates, contributing to a better understanding of gypsum habit in evaporitic environments.

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Section: Effect Of Different Evaporation Rates On Gypsummentioning

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Different Evaporation Rates on Gypsum Habit: Mineralogical Implications for Natural Gypsum Deposits

Cotellucci,

Pellegrino,

Costa

et al. 2023

Crystal Growth & Design

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“…In addition to well-documented geomorphic evidence of karsting during the late Mississippian (McKee and Gutschick 1979;Wenrich and Sutphin 1994;Palmer and Palmer 1995) previously published fossil evidence (DiMichele et al 1996;Falcon-Lang 1999) and isotopic data (Came and Eiler 2006;Grossman et al 2008) also support the presence of a tropical climate at low latitudes.…”

Section: Introductionmentioning

confidence: 72%

Continental paleoclimate estimates from the late Mississippian Redwall karst event: northern and north-central Arizona (USA)

Kenny

2010

Carbonates Evaporites

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The Redwall Limestone of northern and northcentral Arizona (USA) was investigated to determine if suitable secondary silica precipitates were present and which could be used to estimate continental weathering temperatures for the late Carboniferous period. Secondary (authigenic) silica precipitates in lag deposits of chert and residual rubble breccia of oxidized and durable earth material under subaerial weathering during karst events. The Redwall Limestone was extensively karsted for millions of years during the late Carboniferous and suitable secondary silica precipitates were collected from chert lag deposits and residual breccias for isotopic analyses. The stable isotopic (oxygen and deuterium) composition of secondary silica has been successfully used by the author on samples as old as the late Proterozoic to estimate continental paleotemperatures. Isotopic data from secondary silica precipitated during the tropical karst event developed on the Mississippian Redwall Limestone indicate that continental weathering temperatures during the late Carboniferous ranged from *21-34°C.

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Covered Karst Landforms

Veress

2016

Springer Geology

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Grand Canyon caves, breccia pipes and mineral deposits

Abstract: The Redwall Limestone of the Grand Canyon forms a major mineral district, its breccia pipes being host to rich uranium and base‐metal deposits. Yet karst processes as a mechanism for preparing host rocks for ore deposition have been little studied.

Cited by 6 publications

References 2 publications

Effect of Different Evaporation Rates on Gypsum Habit: Mineralogical Implications for Natural Gypsum Deposits

Effect of Different Evaporation Rates on Gypsum Habit: Mineralogical Implications for Natural Gypsum Deposits

Continental paleoclimate estimates from the late Mississippian Redwall karst event: northern and north-central Arizona (USA)

Covered Karst Landforms

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